Merge branch 'master' into gh-pages

* master:
  Add a tooltip in the small multiple.
  Fix the footer link to github.
  Fix the page title.
Add google analytics tracking id.
Merge branch 'gh-pages' into develop

* gh-pages:
  Add google analytics tracking id.
Fix the legend labels.
Merge branch 'develop'

* develop:
  Fix the legend labels.
  Add google analytics tracking id.